A typical flex fuel sensor used in a flex fuel vehicle operates by sampling the capacitance, conductance, and temperature of a given fuel. The sensor outputs the value of the fuel to an electronic engine controller which, along with other inputs, adjusts the fuel air ratio accordingly to make the vehicle's engine run properly.
In the process of manufacturing a flex fuel sensor, a calibration process must be performed to offset minor errors in manufacturing tolerance. In the past, this process was done employing a combination of fuels used in the application. Obviously, this poses a safety problem in the manufacturing environment with a potential fire hazard and forces the manufacturing plant to manage a potentially hazardous material. Subsequently, these fuels were replaced with less volatile test liquids having the same capacitance and conductance as the fuels. However, a problem still exists using a combination of liquids, keeping the concentrations correct, and successfully removing the liquid from the sensor prior to shipment.
Thus, there is a need to provide structure for calibrating a flex fuel sensor without the need to use fuel or other liquids during the calibration.